1. Field of the Invention
The present invention relates to a light emitting diode (LED) illuminating apparatus, and more particularly, to a lamp-type LED illuminating apparatus.
2. Description of the Related Art
Fluorescent lamps and incandescent electric lamps have been used as light sources for illumination so far. The efficiency and economic feasibility of the incandescent electric lamps are lowered due to high power consumption, and hence demands for the incandescent electric lamps tend to be considerably decreased. It is expected that such a decreasing tendency will be continued in the future. On the other hand, the power consumption of the fluorescent lamps is about ⅓ of that of the incandescent electric lamps, and hence the fluorescent lamps are highly efficient and economical. However, the fluorescent lamps have a problem in that blacking of the fluorescent lamps is caused due to high voltage applied to the fluorescent lamps, and therefore, the lifespan of the fluorescent lamps is shortened. Since the fluorescent lamps use vacuum glass tubes into which mercury as a heavy metal is injected together with argon gas, there is a disadvantage in that the fluorescent lamps are non-environmentally friendly.
Recently, demands for a light emitting diode (LED) illuminating apparatus including an LED as a light source have been rapidly increased. The LED illuminating apparatus has long lifespan and lower power driving. Further, the LED illuminating apparatus does not use an environmentally harmful substance such as mercury, and thus is environmentally friendly.
There have been developed various kinds of LED illuminating apparatuses having various structures, and a lamp-type LED illuminating apparatus including a similar form of the incandescent electric lamp or bulb has been developed as one of the LED illuminating apparatuses.
In a conventional lamp-type LED illuminating apparatus, a socket base as a power connection portion is mounted to the bottom of a body portion including a heat sink, a light emitting module having a printed circuit board (PCB) and LEDs mounted on the PCB is mounted to an upper portion of the body portion, and a translucent cover is mounted to cover the top of the light emitting module. The body portion includes the heat sink and an insulative housing, and the heat sink includes a plurality of dissipation fins. The heat sink has a core structure at the inner center of the body portion, and components such as a switching mode power supply (SMPS) and a wire are positioned in the core structure. Here, the SMPS converts AC current into DC current and supplies the converted DC current to the LED in the light emitting module.
In the conventional LED illuminating apparatus, the heat dissipation performance of the heat sink is lowered due to the body portion, the core structure required in the center of the heat sink and several components in the core structure. This results from that the area of the heat dissipation fins exposed to the atmosphere is decreased by the core structure and the insulative housing for covering several components in the core structure. The conventional LED illuminating apparatus has a disadvantage in that it is difficult to decrease the weight of the conventional LED illuminating apparatus due to the core structure and the components such as the SMPS positioned in the core structure, furthermore, the insulative housing as described above.
To decrease the weight of the LED illuminating apparatus, there has been proposed a technique for mounting a driver integrated circuit (IC) on the PCB of the light emitting module, connecting LEDs or light emitting cells or chips in the LEDs in reverse parallel, or integrating a bridge diode circuit in the light emitting module, other than omitting the SMPS for converting the AC current into the DC current. However, even when the SMPS is omitted from the LED illuminating apparatus, the core structure at the inner center of the heat sink exists as it is to accommodate the wire. This becomes an obstacle in reducing heat dissipation characteristics of the LED illuminating apparatus and decreasing the weight of the LED illuminating apparatus.